From 45243aa3ca3f0566e9a8e15b1556c2668d69a39a Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohertj2@Josephs-MacBook-Pro.local>
Date: Tue, 6 Jan 2026 23:23:51 -0500
Subject: [PATCH] feat(ExcelIO): add ExcelClassMap base class with fluent Map
 method

---
 .../Mapping/ExcelClassMap.cs                  | 75 +++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 NEW/src/JdeScoping.ExcelIO/Mapping/ExcelClassMap.cs

diff --git a/NEW/src/JdeScoping.ExcelIO/Mapping/ExcelClassMap.cs b/NEW/src/JdeScoping.ExcelIO/Mapping/ExcelClassMap.cs
new file mode 100644
index 0000000..7f607ef
--- /dev/null
+++ b/NEW/src/JdeScoping.ExcelIO/Mapping/ExcelClassMap.cs
@@ -0,0 +1,75 @@
+using System.Linq.Expressions;
+
+namespace JdeScoping.ExcelIO.Mapping;
+
+/// <summary>
+/// Interface for Excel class maps (non-generic access).
+/// </summary>
+public interface IExcelClassMap
+{
+    /// <summary>The type this map applies to.</summary>
+    Type MappedType { get; }
+
+    /// <summary>Excel table name (for named ranges).</summary>
+    string? TableName { get; }
+
+    /// <summary>Worksheet tab name.</summary>
+    string? TabName { get; }
+
+    /// <summary>Ordered column definitions.</summary>
+    IReadOnlyList<ColumnDefinition> Columns { get; }
+}
+
+/// <summary>
+/// Base class for defining Excel column mappings via fluent API.
+/// </summary>
+/// <typeparam name="T">The model type to map.</typeparam>
+public abstract class ExcelClassMap<T> : IExcelClassMap
+{
+    private readonly List<ColumnDefinition> _columns = [];
+
+    /// <inheritdoc />
+    public Type MappedType => typeof(T);
+
+    /// <inheritdoc />
+    public string? TableName { get; private set; }
+
+    /// <inheritdoc />
+    public string? TabName { get; private set; }
+
+    /// <inheritdoc />
+    public IReadOnlyList<ColumnDefinition> Columns =>
+        _columns.OrderBy(c => c.Order).ThenBy(c => c.PropertyName).ToList();
+
+    /// <summary>
+    /// Configures the table and tab names for this model.
+    /// </summary>
+    protected void Table(string tableName, string tabName)
+    {
+        TableName = tableName;
+        TabName = tabName;
+    }
+
+    /// <summary>
+    /// Maps a property to an Excel column.
+    /// </summary>
+    protected ColumnBuilder<T, TProperty> Map<TProperty>(Expression<Func<T, TProperty>> property)
+    {
+        var memberExpr = property.Body as MemberExpression
+            ?? throw new ArgumentException("Expression must be a property access", nameof(property));
+
+        var propertyName = memberExpr.Member.Name;
+        var compiled = property.Compile();
+
+        var definition = new ColumnDefinition
+        {
+            PropertyName = propertyName,
+            PropertyType = typeof(TProperty),
+            ValueGetter = obj => compiled((T)obj),
+            HeaderText = propertyName // Default to property name
+        };
+
+        _columns.Add(definition);
+        return new ColumnBuilder<T, TProperty>(definition);
+    }
+}